IJITE Vol.04 Issue-04, (April, 2016) ISSN: 2321-1776 International Journal in IT and Engineering, Impact Factor- 5.343 A Monthly Double-Blind Peer Reviewed Refereed Open Access International e-Journal - Included in the International Serial Directories International Journal in IT and Engineering http://www.ijmr.net.in email id- irjmss@gmail.com Page 21 The magnetic investigations of indium substituted cobalt ferrite nanoparticles A.B. Shinde Nano Materials & Lasers Research Laboratory, Dept.of Physics, Abasaheb Garware College, Karve Road, Pune -411004,Maharashtra, INDIA Abstract: The nanocrystalline In 3+ substituted cobalt ferrite having molecular formula CoIn x Fe 2-x O 4 (x= 0.0,0.1,0.2,0.3,0.4,0.5) have been synthesised by sol-gel auto combustion technique. The magnetic properties were studied with the help of pulse field hysteresis loop tracer technique. The saturation magnetisation decreases with increase in In 3+ substitution x. The temperature dependence of field cooled (FC) and zero field cooled (ZFC) magnetisation of indium substituted cobalt ferrite nanoparticles. Keywords: Sol-gel, nanocrystalline, FC and ZFC Introduction: In the recent years, interest in nano size materials has increased due to their unusual physical and chemical properties which often differ from the bulk. The difference in the properties of nano size materials is attributed to the increase in surface area along with decreased particle size and various size effect [1-2]. The nano- size materials have become the focus of interest for several researchers not only due to their superior properties but they have many technological applications in recording media, drug delivery, catalyst, sensors, biomedical engineering and other fields [3-4]. Much attention has been recently devoted to the nano particles of spinel ferrite systems. Nanostructured iron oxide containing transition metal oxide materials are known to exhibit interesting physical and chemical properties, significantly different from bulk materials, because of their smaller size and large specific surface area. Ferrites are defined as magnetic materials composed of iron oxide as their main constituent and metal oxides. Ferrites possess both electrical and magnetic properties and have many applications in electronic computer, medical, automobile and other areas. In the family of ferrites, cobalt ferrite with spinel structure have attracted scientists and technologists because, cobalt ferrite is a hard magnetic material with high coercivity, moderate magnetization, high Curie temperature and excellent chemical stability [5-6]. The high electrical resistivity and negligible eddy current losses makes cobalt ferrite useful in high frequency magnetic applications, magnetic recording applications (audio-video tapes) and high density digital discs etc [7]. The cobalt ferrite has cubic inverse spinel structure with Co 2+ ions occupying half of the octahedral [B] sites whereas Fe 3+ ions occupy all tetrahedral (A) sites and half of the octahedral [B] sites [8]. In addition to these remarkable features, the cobalt ferrite exhibits large magneto crystalline anisotropy along with (100) crystallographic direction and large magnetostriction in bulk form. Nano size cobalt ferrite has been prepared by using physical and wet-chemical methods. Wet-chemical methods are particularly interesting and advantageous for their low cost, ease of preparation, low temperature synthesis, smaller particle size, good chemical stability and homogeneity. The wet-chemical methods include hydro-thermal [9], sol-gel [10], chemical co-precipitation [11], micro-emulsion [12], sono-chemical [13]. The sol gel auto combustion method is a well known and commonly used technique which produces high purity, homogenous powders with nano meter dimension. In the literature, a lot of work has been reported about synthesis and magnetic properties of cobalt ferrite synthesized by various methods [14-17]. A review of literature shows that very limited work has been done on infrared and cation distribution studies of nanocrystalline